This year, instead of sending the message that YouTube is a replacement for TV, the search giant has a fresh tactic: arguing that YouTube actually is TV.

Specifically, YouTube is rolling out a new offering that will enable advertisers to target their ads to people who watch YouTube on TV screens, using devices like Rokus, Xboxes, Chromecast and Amazon Fires.

While Google executives have long talked up the massive reach YouTube commands among young people, particularly using mobile devices, during recent earnings calls the company has started noting the growing number of people accessing YouTube on big screens in their living rooms.

That YouTube-on-the-tube audience is going to be a key focus when Google hosts its 'Brandcast' event for top advertisers and ad buyers in New York this Thursday.

"We had a lot of conversations about mobile the last couple of years," said Debbie Weinstein, managing director for YouTube/Video Solution. "However, TV screens are our fastest growing surface. And now it's meaningful enough that we can build a real business."

YouTube says that globally, people are streaming 150 million hours a day of YouTube content on TV screens. That's up from 100 million hours a day last October, according to Recode.

As of March of 2018, nearly 30 million US homes had streamed YouTube to their TVs, out of nearly 60 million homes that streamed any web content on their TVs, reported comScore.

Overall, 65% of the time spent on YouTube was on mobile, 22% on desktop devices, and 13% on connected TVs.

Weinstein said that Google is seeing viewership patterns for YouTube on TV screens that are more TV-like: longer viewing sessions, less 'how-to' instructional fare, and more lean-back entertainment.

Meanwhile, there's a growing appetite in the ad world to advertise to people watching TV 'over the top' (OTT), a tactic which theoretically blends the best of big screen television advertising with the data and precision of digital.

But to date, most OTT consumption has been driven by Netflix, HBO and Amazon - services that don't carry ads.

YouTube is a growing OTT player comScore

So helping advertisers reach the increasingly hard-to-reach streaming audience is potentially a good story for YouTube. And it's surely a lot better story than the ongoing string of brand safety disasters for YouTube.

YouTube is also set to announce on Thursday that it will start selling ads via its fledgling pay TV subscription service YouTube TV, which is available in 99 of the top 100 TV markets. And besides rolling out new ad options for YouTube on TV, the company also has a new product that will help advertisers target 'light TV viewers.'